Ok. First of all, inspect everything to make sure it's not beat-up and all is good.
You will need to install the power supply (most cases come with it already in). Can't really advise you there, every case I have ever owned has come with the PSU I wanted (I shop with PSU in mind).
From here, put the case plate that came with the motherboard into the slot for it in the case. Now you need to insulate the back of your motherboard, behind the CPU socket. This in due to the fact you are planning on sub-zero cooling (peltier/phase) and need to prevent the condensation that would ever so badly LOVE to eat your motherboard. Check the extreme cooling section of these forums to see how to insulate.
Once that's all taken care of, the next step is to put the mounting thingies (brass screw-in's) into the case. You want to line them up with your motherboard's mounting holes. Once those are in, place your motherboard in (GENTLY!) and then use the screws it came with to mount it into place.
Now you want to put the jumpers into the place. Look them up online, in the manual, or with the sticker the NF7-S comes with (or at least mine did). The jumpers are the small cables that came already in the case (usually towards the bottom right). They control the LED's in the case (power + hard drive), power button, reset button, and computer speaker.
Now, you need to put Thermal electric grease onto the CPU socket, again to prevent condensation. Be careful! Now put the CPU into place (making sure to have cleaned the junky thermal stuff it comes with off of it, if it comes with any) and apply Artic Silver 3/5. Only use a Tiny amount, you want the thinnest layer of this stuff you can. Next, you should mount your Water block/Peltier onto the CPU. Depending on if it's hold-down or screw-mount, mount the block onto the CPU (be careful again, easy to break a CPU!). Now insulate this stuff, again the condensation would love to kill the computer.
Onto RAM. Put your Ram into the computer (make sure you are putting it in the right way). Oddly enough, that's all you need to do with RAM (unless you're getting dual channel, in which case you need to put it into place in the specific manner described in the motherboard booklet.
Next you should mount your CD/DVD drives, Hard Drives, and Floppy Drives into place. Just place them into the corresponding bays and use the screws provided to hold them there. Now take the IDE cable (big wide cable) and plug it into the motherboard (blue end usually goes into the motherboard). Next plug one end into one CD Drive, and the middle cable into the next. Not, take the other IDE cable, plug it into your hard drive, (if you have more then 1 HD, do the same as CD drive, but make sure the Hard Drive jumpers are in right settings) and then put the other side into the motherboard. Next take the floppy bay IDE cable and connect it to the bay (and add the cable to the motherboard).
Onto the cards. Take your video-card and place it into the AGP/PCI slot (PLEASE get an AGP card, unless you are getting a top-of-the-line PCI Express card). Place any other cards you need into the PCI slots.
Now are are going to put in fans! It start's really coming together now. Take the case fans you want, and place them where you want them. Then use the screws they came with and attach them to the case. Almost looks like a computer now.
Time to power things. Take the really big connector (20-pin molex) and plug it into the slot for it in the motherboard. Then take the square molex pin and plug it into the motherboard (at least I have to in mine). Next you take a 4-pin molex chain from the power-supply and plug it into the hard-drive. Try not to connect to much on this change, sometimes hard drives can die due to other things on the chain. Next plug 4-pin molex'd into the CD/DVD drives. Then plug a "floppy drive" molex into the floppy drive. Now plug in your case fans (come case fan's take a 3-pin, which has plugs for it on the motherboard).
That should cover you for now at least.
